American Airlines was forced to ground all of its flights for several hours Tuesday after experiencing a nationwide problem with its computer systems. By late afternoon, its computers were back up and its operation were slowly coming back to life.
More than 400 flights were canceled and scores more were delayed after a systemwide problem that started around midday and lasted until around 3:30 p.m. Central time.
The airline said it expected cancellations and delays through the rest of Tuesday, with schedules beginning to return to normal Wednesday.
American said the issue was caused by an inability to get access to its reservations system, called Sabre.
The electronic system, often described as the brains of an airline, is responsible for bookings and reservations but also manages a wide variety of functions related to flights, including printing boarding passes, online check-ins, ticketing and tracking checked bags.
While the cause of the problem was not immediately clear, the airline emphasized that the problem was not related to the attacks in Boston on Monday.
Sabre, meanwhile, said American’s system problem did not come from its own computer systems. Other airlines, including Southwest Airlines and JetBlue, use the reservation system and have not experienced any problems, said Nancy St. Pierre, a spokeswoman for Sabre.
Such nationwide breakdowns are rare but not unprecedented, particularly when airlines merge. United Airlines experienced similar problems last year when its reservation systems failed repeatedly as it merged them with those of Continental Airlines.
But while American Airlines, which is still in bankruptcy restructuring, has agreed to merge with US Airways, the two airlines are nowhere close to integrating their systems because the planned merger still needs to clear regulatory hurdles.
American said that its network system had experienced “intermittent problems,” which led it to ground the fleet. The airline said it would waive fees for passengers who wanted to change their reservation on Tuesday and refund those who wished to cancel their flight.
At Dallas-Fort Worth International Airport, thousands of passengers were stranded and waiting for flights, some of which were being canceled. Some passengers described being stuck for long stretches on planes on the runway unable to take off or, having landed, initially unable to get to a gate.